Heretofore, a polishing tape having abrasive particles has been employed to polish a notch portion formed in a semiconductor wafer. Specifically, a polishing tape is brought into contact with a notch portion of a semiconductor wafer and moved in a direction perpendicular to a surface of the wafer to polish the notch portion of the wafer.
In this conventional method, a polishing tape is deformed along a notch portion of a wafer under a polishing load. Edge portions of the polishing tape may scratch the notch portion of the wafer according to polishing conditions. Accordingly, a wafer may be flawed or unevenly polished at the notch portion according to polishing conditions. Further, if the polishing tape is insufficiently deformed, an area of the polishing tape contacting the wafer is reduced so that it is difficult to conduct stable polishing. In this case, it is difficult to achieve uniform polishing. Additionally, it is uneconomic in that the entire surface of the polishing tape is not used for polishing. Further, if an area of the polishing tape contacting the wafer is small when a curved surface is polished, the wafer needs to be divided into several small areas, which are sequentially polished. Accordingly, it takes much time to complete the polishing process.
Thus, if polishing conditions are improperly set when the notch portion of the wafer is polished, there arise problems such as scratches on the wafer by the edge portions of the polishing tape or unevenly polishing. In order to overcome such problems, a polishing tape may be thinned so as to accord with a shape of the notch portion. However, when a polishing tape is thinned, resistance to tension is reduced. Thus, the polishing tape has a limitation of the thinness.